The present invention is directed, in general, to electronic data storage technology and, more specifically, to an apparatus and method for providing a significant reduction in the power consumption of an electronic data storage system. The present invention is especially useful in providing a significant reduction in the power consumption of battery operated flash memory data storage systems.
A non-volatile data storage device is one that retains the data stored in it when external power to the device is shut off. One of the earliest non-volatile storage devices was punched paper tape. One of the most recent technologies for storing data in a non-volatile electronic data storage device is called xe2x80x9cflash memory.xe2x80x9d Flash memory is a programable semiconductor memory of a type called xe2x80x9cread-mostlyxe2x80x9d memory. Flash memory is so named because of the speed with which it can be reprogrammed. Flash memory uses an electrical erasing technology that can erase an entire flash memory array in a few seconds at most. Data written to flash memory remains in a non-volatile storage mode until the flash memory is deliberately erased. Flash memory requires a relatively high level of current (and a high level of electrical power to provide that current) when data is being written to the flash memory. A typical value of current required by flash memory when data is being written to the flash memory is sixty milliamps (60 mA).
CompactFlash(trademark) memory is a relatively new flash memory data storage system. CompactFlash(trademark) is a registered trademark of SanDisk Corporation. CompactFlash(trademark) memory is very useful in various types of technological applications and represents a significant advance over other flash memory data storage systems for a number of reasons. In comparison with other flash memory data storage systems, CompactFlash(trademark) memory has greater speed, greater durability, and smaller size. It is also packaged in a form that is very compatible with personal computers, especially laptop computers. CompactFlash(trademark) memory makes it possible to store several tens of Megabytes of data on a memory card that is no larger than an ordinary matchbook. CompactFlash(trademark) memory cards are now being used in digital cameras, in personal data assistants (PDAs), in MP3 audio players, and in other similar electronic data storage devices.
One of the drawbacks of CompactFlash(trademark) memory (and of flash memory data storage systems in general) is that its operation requires a relatively high level of current. The greater the speed with which a flash memory data storage system is accessed, the more current it requires for operation. Even at the slowest access speeds, flash memory data storage systems generally require a comparatively large amount of current for operation.
For this reason flash memory data storage systems have not been widely used in battery powered devices for gathering electronic data. This is especially true for battery powered devices that acquire data slowly over a relatively long period of time. The power requirements of a flash memory data storage system in such a device would require continual and frequent replacement of the batteries. In many applications this requirement would make the use of a flash memory data storage system impractical.
It would be advantageous to have a flash memory data storage system in which the power consumption is reduced compared to the power consumption in prior art flash memory data storage systems. It would also be advantageous that any reduction of the power consumption in such a flash memory data storage system be achieved without a corresponding reduction in the performance level of the flash memory data storage system.
To address the deficiencies of prior art electronic data storage systems, and especially those that require a relatively high level of current (and power) when data is being written to them, it is a primary object of the present invention to provide an improved electronic data storage system in which the power consumption of the electronic data storage system is reduced compared to the power consumption of prior art electronic data storage systems.
It is also an object of the present invention to provide an improved flash memory data storage system in which the power consumption of the flash memory data storage system is reduced compared to the power consumption in prior art flash memory data storage systems.
It is a further object of the present invention to provide an improved flash memory data storage system in which the reduction of the power consumption in the flash memory data storage system is achieved without a corresponding reduction in the performance level of the flash memory data storage system.
It is an additional object of the present invention to provide an improved flash memory data storage system for use in battery powered devices for gathering electronic data.
It is yet another object of the present invention to provide an improved flash memory data storage system for use in battery powered devices that acquire data slowly over a relatively long period of time.
Accordingly, in an advantageous embodiment of the present invention, there is provided, for use with a memory data storage device that operates in a high power mode when data is being written therein and operates in a low power mode when inactive, a system for minimizing a power consumption level of the memory data storage device comprising: 1) a controller capable of receiving incoming data to be written to the memory data storage device; and 2) a first low power buffer coupled to the controller, wherein the controller stores the incoming data in the first low power buffer until a predetermined amount of incoming data has been accumulated in the first low power buffer and wherein the controller transfers the accumulated predetermined amount of incoming data to the memory data storage device in a single data transfer.
In one embodiment of the present invention, the predetermined amount of incoming data is determined by a size of the predetermined amount of incoming data.
In another embodiment of the present invention, the size of the predetermined amount of incoming data is five hundred twelve bytes of data.
In still another embodiment of the present invention, the predetermined amount of incoming data is determined by a selected time duration during which the predetermined amount of incoming data has been accumulated.
In yet another embodiment of the present invention, the controller transfers the accumulated predetermined amount of incoming data to the memory data storage device when the memory data storage device is in the high power mode.
In a further embodiment of the present invention, the system further comprises a second low power buffer coupled to the controller capable of storing the incoming data when the accumulated predetermined amount of incoming data is being transferred from the first low power buffer to the memory data storage device.
In a still further embodiment of the present invention, the memory data storage device is of a battery powered type having a relatively high power consumption when data is written to the memory data storage device.
In a yet further embodiment of the present invention, the memory data storage device is a flash memory card.
The foregoing has outlined rather broadly the features and technical advantages of the present invention so that those skilled in the art may better understand the detailed description of the invention that follows. Additional features and advantages of the invention will be described hereinafter that form the subject of the claims of the invention. Those skilled in the art should appreciate that they may readily use the conception and the specific embodiment disclosed as a basis for modifying or designing other structures for carrying out the same purposes of the present invention. Those skilled in the art should also realize that such equivalent constructions do not depart from the spirit and scope of the invention in its broadest form.
Before undertaking the DETAILED DESCRIPTION OF THE INVENTION, it may be advantageous to set forth definitions of certain words and phrases used throughout this patent document: the terms xe2x80x9cincludexe2x80x9d and xe2x80x9ccomprise,xe2x80x9d as well as derivatives thereof, mean inclusion without limitation; the term xe2x80x9cor,xe2x80x9d is inclusive, meaning and/or; the phrases xe2x80x9cassociated withxe2x80x9d and xe2x80x9cassociated therewith,xe2x80x9d as well as derivatives thereof, may mean to include, be included within, interconnect with, contain, be contained within, connect to or with, couple to or with, be communicable with, cooperate with, interleave, juxtapose, be proximate to, be bound to or with, have, have a property of, or the like; and the term xe2x80x9ccontrollerxe2x80x9d means any device, system or part thereof that controls at least one operation, such a device may be implemented in hardware, firmware or software, or some combination of at least two of the same. It should be noted that the functionality associated with any particular controller may be centralized or distributed, whether locally or remotely. Definitions for certain words and phrases are provided throughout this patent document, those of ordinary skill in the art should understand that in many, if not most instances, such definitions apply to prior, as well as future uses of such defined words and phrases.